Urban structures exhibit complex patterns made of heterogeneous and irregular objects. Few works in the computational urban modelling literature have considered and examined the real geometric boundary of the city’s objects. However, most of these works are driven by Cellular Automata (CA) as a spatial modelling vehicle. This model has had success, but also has its limitations regarding the study of urban dynamics in computer simulation. Extensive modification of CA or use of a different modelling paradigm should be considered. We argue here that, representational realism must be achieved in urban complexity. This paper is an attempt to fill this gap to address the rigid structure of CA: we present a novel technique called the “vector-agent based simulation”, which uses discrete irregular objects as an autonomous spatial entity beneath an agent modelling structure. Through computer simulation, this new technique has been applied to von Thunen’s theory of agricultural land use as a hypothetical environment for model verification. The findings demonstrate that our proposal can be a new paradigm for urban simulation